1. Field of the Invention
This invention relates to a panel structure for surface-discharge-type AC plasma display panels.
The present application claims priority from Japanese Application No. 2003-80179, the disclosure of which is incorporated herein by reference.
2. Description of the Related Art
Surface-discharge-type AC plasma display panels have recently gained the spotlight as types of large-sized slim color display apparatus and are becoming increasingly common in homes and the like.
FIGS. 1 to 3 are schematically structural diagrams of the conventional surface-discharge-type AC plasma display panels, FIG. 1 being a front view, FIG. 2 being a sectional view taken along the V—V line in FIG. 1 and FIG. 3 being a sectional view taken along the W—W line in FIG. 1.
Referring to FIGS. 1 to 3, the plasma display panel (hereinafter referred to as “PDP”) has a front glass substrate 1 of which one surface serves as the display screen and on the other surface are formed in order a plurality of row electrode pairs (X, Y), a dielectric layer 2 covering the row electrode pairs (X, Y) and an MgO made protective layer 3 covering the back surface of the dielectric layer 2.
The row electrodes X, Y are individually composed of transparent electrodes Xa, Ya each formed of a large-wide-shaped transparent conductive film made of ITO or the like, and bus electrodes Xb, Yb each formed of a small-wide-shaped metal film assisting the conductivity of the corresponding transparent electrode.
The row electrodes X and Y are arranged in alternate positions in the column direction (i.e. the vertical direction in FIG. 1). The adjacent two row electrodes X, Y in this arrangement face each other with a discharge gap gin between to constitute a row electrode pair (X, Y) forming a display line L in matrix display.
The front glass substrate 1 is opposite a back glass substrate 4 with a discharge-gas-filled discharge space S in between. On the inner surface of the back glass substrate 4 opposing the front glass substrate 1, a plurality of column electrodes D each extending in a direction at right angles to the row electrode pairs (X, Y) are regularly arranged. A belt-shaped partition wall 5 extends in parallel between the adjacent column electrodes D. Further phosphor layers 6 individually made of red (R), green (G), and blue (B) phosphor materials each cover the side faces of the partition walls 5 and the column electrode D between the partition wall 5 concerned.
In each display line L, the partition walls 5 delimit the discharge space S at intersections of the column electrodes D and the row electrode pair (X, Y) to define discharge cells C each forming a unit light-emitting area.
The PDP having the foregoing structure is described in Japanese Patent Laid-open Application No. 9-167565.
The surface-discharge-type AC plasma display panel displays images as follows:
In an addressing period subsequent to a reset period for causing a reset discharge, a discharge (addressing discharge) is caused between the column electrode D and one row electrode in the row electrode pair (X, Y) (in this case, the row electrode Y) in each of the selected discharge cells C. As a result, the lighted cells (the discharge cells having wall charges generated on the dielectric layer 2) and the non-lighted cells (the discharge cells having no wall charges generated on the dielectric layer 2) are distributed over the panel surface in accordance with the image to be displayed.
After completion of the addressing period, simultaneously in all the display lines L, a discharge-sustaining pulse is applied alternately to the row electrodes X and Y in each row electrode pair. Thereupon, due to the wall charges accumulated on the dielectric layer 2, a sustain discharge is produced between the row electrodes X and Y in each lighted cell with every application of the discharge-sustaining pulse.
As a result of the sustain discharge in each lighted cell, ultraviolet light is generated and excites each of the red-, green- and blue-colored phosphor layers 6 in the individual discharge cells C to emit visible light for the generation of the image.
In the conventional three-electrode surface-discharge-type AC PDPs structured as described above, the addressing discharge and the sustain discharge are caused in the same discharge cell C. That is, the addressing discharge produced in each discharge cell C passes through the red (R), green (G), or blue (B) phosphor layer 6 which is formed for emitting colored light by means of the sustain discharge produced in the discharge cell C concerned.
Under these circumstances, the addressing discharge caused in each discharge cell C is affected by elements in the phosphor layer 6 such as discharge properties varying with each color of the phosphor material forming the phosphor layer 6, variations in the layer thickness produced in the forming process for the phosphor layer 6, and the like. Therefore, the conventional PDPs have the problem of significant difficulty in providing the equivalent addressing-discharge properties in each discharge cell C.
In order for the foregoing conventional three-electrode surface-discharge-type AC PDPs to increase the surface area of the phosphor layer 6 for an increase in luminous efficiency, there is a need to expand the discharge space inside each discharge cell C. To meet this need, the method of increasing the height of the partition wall 5 has been conventionally employed.
However, increasing the height of the partition wall 5 for an increase in luminous efficiency results in an increase in the distance between the row electrode Y and the column electrode D in which the addressing discharge is produced, leading to the problem of needing to boost the voltage for starting the addressing discharge.